module top_module( 
    input [2:0] a, b,
    input cin,
    output [2:0] cout,
    output [2:0] sum );

    assign {cout[0], sum[0]} = cin + a[0] + b[0];
    assign {cout[1], sum[1]} = cout[0] + a[1] + b[1];
    assign {cout[2], sum[2]} = cout[1] + a[2] + b[2];
    
endmodule
